I didn't want to start a new thread on this but I've searched the archives and found numerous suggestions, from adding B12 to replacing mils, etc. What is the surest way to methodically pin down the cause? '99 Contour SE, Duratec V6, ATX, 93000 miles. Thanks muchly.
the simple answer is the cats are cooked and need to be replaced
or your sensors are shot and making a false P0420 and P0430
This TSB shows some of the causes of the 420 and 430 codes. You may want to try some of the "fixes" first. Your other options are to reprogram the computer (about $200) or mileliminators ($30) or new pre-cats (mucho deneiro).
It is unlikely that both HO2 sensors are shot, but still possible, I imagine. I'll search for a procedure to test the ECT as well, or just replace it. If my cats are shot would I need to replace the main cat also? Or just the precats and then we see how it goes? The whole mileliminator thing scares me...is that legal? Thanks once again.
Originally posted by dave5000:
It is unlikely that both HO2 sensors are shot, but still possible, I imagine. I'll search for a procedure to test the ECT as well, or just replace it. If my cats are shot would I need to replace the main cat also? Or just the precats and then we see how it goes? The whole mileliminator thing scares me...is that legal? Thanks once again.
You'd just have to replace the precats because your P0420 and P0430 are directly related to those. Your main cat is further back in the exhaust system...
And technically, No, it's not legal to put mils on your car. Your O2 sensors are there to ensure your car is running at it's best and putting out clean exhaust.
Thanks Woodencross...I believe I'm all set here now. You guys are the greatest. Really!
This just happened to my wifes car the other day also. But I have a suspicion about the gas when we were filling up they were also filling the main tanks. After clearing the double code I have gotten 2 bank 2 codes since then. But it has been going well for almost a week now. I had also put a K&N on a little while ago and I thought maybe some oil got on the MAF. Cleaned that up also since it was easy.
For a car with almost 100000 miles on it I wouldn't bother replacing the precats just get the eliminators and think of it as a reflash. I have a feeling your car is still running well anyways. And if they did check your emissions it would still be well below there limits. Why else do you think ford is just reflashing now. Saves them money and isn't necessary to replace them.
Downstream sensors don't cause these codes. They are self-tested prior to execution of the cat efficiency test. Gasoline quality is also not an issue. Same for the MAF.
Your choices are:
PCM reflash
MIL Eliminators
New pre-cats
Black tape over the CEL
Ignoring the CEL completely
Steve
i don't agree with the gas comment, I think it can deal with the gas
the only time I got a precat code was when I had a bad sensor when I got the car
come to SZ06 and going out to Indiana, car starts to throw P0420 about half way out and all the way back, with in a few weeks I start getting a code P0430 then they went away completely. All I can figure is the gas was the issue as after a tank or two of CT gas again the code have not come back since
Originally posted by dave5000:
It is unlikely that both HO2 sensors are shot, but still possible, I imagine. I'll search for a procedure to test the ECT as well, or just replace it. If my cats are shot would I need to replace the main cat also? Or just the precats and then we see how it goes? The whole mileliminator thing scares me...is that legal? Thanks once again.
Just realize I did not post the link to the TSB.
http://www.v8sho.com/SHO/TSB0197HO2SServiceTips.htm
Not sure if you have to deal with inspections. Some have posted that the pre-cats are not necessary to assist in passing emissions tests but some have posted that they are. Bear in mind that the pre-cats cost about $700 each plus labor (so you are looking at $2000) if you want to replace them. The reprogramming by Ford just widens the band of limits before the CEL light comes on (not sure how long that is good for). Not really sure if mileliminators are legal or not but the way I see it (for me), it is widening the band of limits too. I have mileliminators now (and did not gut my pre-cats). I will know if I need to do more in May when I go for my smog emissions tests.
I think I'm going to go with...ignoring the CEL completely, at least for now. I'm in NY where they no longer test your actual exhaust. They used to but not anymore on 1999 vehicles and newer. They hook up to the car and check for codes, plus a visual on the lights and brakes and such, and then you are done.
After I cleaned the UIM and cleared my EGR code I took a 60 mile drive and went back for my inspection(which I passed). It took another 40 miles for the CEL to pop up with the 420 and 430 codes. If I can pass inspection after one drive cycle and the 420's and 430's don't appear until after perhaps 6 drive cycles, I know how to go about my inspection next October. If it doesn't work out I'll then have to do something about it. As a civil servant I know one thing...when in doubt, do nothing!(Maybe that should be my sig LOL)
I will print and save this thread though as there is a ton of good info here.
Originally posted by dave5000:
I think I'm going to go with...ignoring the CEL completely, at least for now. I'm in NY where they no longer test your actual exhaust. They used to but not anymore on 1999 vehicles and newer. They hook up to the car and check for codes, plus a visual on the lights and brakes and such, and then you are done.
After I cleaned the UIM and cleared my EGR code I took a 60 mile drive and went back for my inspection(which I passed). It took another 40 miles for the CEL to pop up with the 420 and 430 codes. If I can pass inspection after one drive cycle and the 420's and 430's don't appear until after perhaps 6 drive cycles, I know how to go about my inspection next October. If it doesn't work out I'll then have to do something about it. As a civil servant I know one thing...when in doubt, do nothing!(Maybe that should be my sig LOL)
I will print and save this thread though as there is a ton of good info here.
My CEL came on my '99 also at about 90,000+ miles, with the same codes. My mechanic said not to worry about it, so I've been ignoring the lit CEL for almost 100,000 miles now. I keep hoping it will burn out one of these days. 
Hi Dave,
I have 95,000+ miles on my Contour V6 SE and I 'had' the 420 code appear back at 82,000 miles -- but not since then.
The solution was to put a can of 'Seafoam' OR a can of 'Berryman's B12' in the gas tank at EVERY fillup. It took 4 fillups before the CEL *stayed* out. I have a Matco 9620 code scanner (ebay) so I could 'clear' the codes without having to do the battery or fuse fandango.
I routinely put a can of Berryman's B12 in 'every other full tank' ...and have NOT had an iota of a CEL (or similar problem) since.
As the guyz n gals constantly recommend here ...START with the cheap and simple stuff FIRST.
Good luck!
Gerry
I thought the routine was to use the sea foam or b12 when the tank was low and run for a while. I also thought there was a series of posts on this some time back. The theory is the cats get hotter and burn off build up. I just got one of the codes on the SVT and cleared to see if it comes back. My car is up for inspect and in NJ if the check engine light is on you will fail. They actually plug in the OBD II port during inspection.
Rich S
Hi,
If the CEL is 'on' then, for goodness sake, do NOT bring the car in for inspection. INSTANT FAILURE!!!
Do not try and 'trick' the system either - by clearing the codes (yanking fuses or disconnecting battery) as the 'readiness codes' will NOT be set and you will ALSO fail inspection. (The 'readiness codes' take about 30 miles of 'various types of driving' before they will set to 'OK' -- which means there's a VERY good chance that the CEL will ALSO come on during that time.) Yeah, I know, bogus.
If the cats are 'marginal' you can 'attempt' to clear them out using i) Catalytic Converter Cleaner or ii) Berryman's B12 or iii) Seafoam.
I've found that Seafoam causes a lot of 'smoke out the exhaust' so running it in a car with little or no fuel may turn yer vehicle into a smoke bomb! (You'll be VERY unpopular with the neighbors!)
If you are stuck for 'time' then you could do this:
a) empty out a windex spray bottle
b) fill it up with Berryman's B12 or Seafoam or cat-cleaner
c) disconnect your air filter so that you have access to the intake manifold (i.e. when you "look in" you can see the MAF and the throttle butterfly (valve).
d) when the engine is warmed up and running -- spray the contents of the 'spray bottle' into the intake manifold until it's all used up.
Try not to spray 'downwards' otherwise you'll end up with a useless 'puddle' of fluid on the accordion part of the manifold tubing. Rather, "gun" the engine (so that the butterfly is 'open' a smidge') THEN spray "into" this opening.
Good luck!
Gerry
Hope Chad posts into this..just ask him about my car and the seafoam
There are many Berryman's B12 products available; which one do you guys reccomend to try to eliminate this cel 0420?
3 to 4 tankfuls of Berrymans B12 Liquid (non-aerosol).
Ray
Full tank, half tank, 1/4 tank,...?
I'll give it a shot; I can't keep the code from coming back after I clear it, no matter what I've tried...short of replacing the CAT and that would be my LAST alternative.
